So I've been watching some platinum and challenger matches b/c why not, and I'm starting to notice that mid laners opt to leave a turret standing, or not push and get damage it, etc quite frequently. Can someone enlighten me as to why this is a good idea? I usually try and burst the turret down as fast as possible, which allows me more freedom to roam, as well as more room to chase people if I have to.
One reason is that the turrets help deny farm. If a midlaner shoves to turret, he can recall or roam while his minions are dying to the turret (and they're still doing damage to it). A lot of players consider laning phase over once a turret drops, and knocking one down too early might cause some confusion with regards to farming and grouping. Also, if you want to continue farming in lane, you might be forced to play deeper into the enemy's territory if he plays defensively, leaving you open to ganks.
as well as more room to chase people
There are few times where you should actually be in a chase, it's usually a waste of time or leading you into their team.
On the note of turrets, it depends on the lane. Tops will usually push their turret down then proceed to roam however most mids will push the wave toward the enemy as soon as they hit 6 and move to roam. It occupies the opposing midlaner and forces them to choose between minions doing tower damage and following their opponent or staying and having a 3v2 or 2v1 in a lane not including jungle presence. Reason for that being your mid is almost always your AP carry, they likely have a better use elsewhere picking up kills or at least assists than sitting in mid and farming endlessly.
Certain mids, mostly mobile assassins with weaker laning phases in comparison to other mids (ex. Katarina, Zed, Talon) will roam at 6 to pick up kills elsewhere more safely than to stay in midlane and become quickly irrelevent.
Pushing past 1 turret without boots and good warding is just asking for getting a 3 player gank. Often with low turret health (if you leave it at let's say 20%) the enemy player will try to prevent damage to the turret by tanking minion waves which makes the lane a lot more in your advantage.
I personally prefer to not take the turret when: I don't have upgraded boots of speed. I'm not level 9 yet.
It's different though if I'd be on the bottom lane, I'd prefer not to take the turret when: My support/ADC or me doesn't have upgraded boots of speed. My support doesn't have a Sightstone yet. I'm not level 9 yet and/or my support/ADC isn't level 9 yet.
I have one. Once the tower falls your opponent doesn't need to defend it anymore (obviously). If their champ is innately better at roaming than yours is you could be in trouble.
I was on the receiving end of this once. Due to some miscommunication during champ select, I was playing Rumble against Syndra in mid and got dumpstered hard, going 1/6/0. While my tower was up, Syndra didn't wander and I felt like I needed to keep trying to keep the tower alive even though I knew it wouldn't go well for me. Very shortly after my tower fell I joined my jungler for a gank on bot lane and my team got 2 kills and possibly more out of that (it was a bit ago that this happened), and that let our team keep snowballing and their fed Syndra couldn't do enough to stop us.
If I understand it correctly, it lets you deny farm to the enemy laner. If youre shoving them under turret, a lot of players will miss some of every wave due to mismanaged attacks with turret damage. You can even deny an entire wave if your opponent backs and you push an entire group under his tower, which can be extremely important in the early game.
As others have said it will also pretty much force your laner to hang around in lane to protect the objective instead of roaming to help other lanes (which you can do since youre likely pushing them under turret).
Im sure there is an ideal time where not killing a tower becomes sub-optimal, though im not sure when that would be.
its a time efficiency thing. unless you have a lot of AD, it's hard to take down a turret. that time could be better spent buying, warding, invading, or roaming to help other lanes in many cases. also, shoving a wave into a turret and then leaving immediately causes it to push back towards you. in the early game this is the easiest way to generate a CS advantage since your opponent loses all the minions killed by the turret as well as many more when the wave starts pushing.
As many people have pointed out, it's for minons deny and safety.
Unless you plan to hard push or gank other lanes constantly, it's best to prolong your "main laning phase" a bit, also, if you're ahead of the enemy it also gives you more chance to kill them a few more times.
